Thermal balance of Nellore cattle

Author(s)

de Melo Costa, Cintia Carol ; Campos Maia, Alex Sandro ; Nascimento, Sheila Tavares ; Nagib Nascimento, Carolina Cardoso ; Neto, Marcos Chiquitelli ; Carvalho Fonseca, Vinicius de Franca

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF BIOMETEOROLOGY; v. 62, n. 5, p. 9-pg., 2018-05-01.

Abstract

This work aimed at characterizing the thermal balance of Nellore cattle from the system of indirect calorimetry using a facial mask. The study was conducted at the Animal Biometeorology Laboratory of the So Paulo State University, Jaboticabal, Brazil. Five male Nellore weighing 750 +/- 62 kg, at similar ages and body conditions were distributed in four 5 x 5 Latin squares (5 days of records and five schedules) during 20 days. Physiological and environmental measurements were obtained from the indirect calorimetry system using a facial mask. Respiratory parameters, hair coat, skin, and rectal temperature were continuously recorded. From this, metabolic heat production, sensible and latent ways of heat transfer were calculated. Metabolic heat production had an average value of 146.7 +/- 0.49 W m(-2) and did not change (P > 0.05) over the range of air temperature (24 to 35 A degrees C). Sensible heat flow reached 60.08 +/- 0.81 W m(-2) when air temperature ranged from 24 to 25 A degrees C, being negligible in conditions of temperature above 33 A degrees C. Most of the heat produced by metabolism was dissipated by cutaneous evaporation when air temperature was greater than 30 A degrees C. Respiratory parameters like respiratory rate and ventilation remained stable (P > 0.05) in the range of temperature studied. Under shade conditions and air temperature range from 24 to 35 A degrees C, metabolic heat production, respiratory rate, and ventilation of mature Nellore cattle remain stable, which is indicative of low energetic cost to the thermoregulation. (AU)

• FAPESP's process: 11/16695-2 - Effect of solar radiation and temperature on methane emissions associated to heat production and heat loss in cattle
• Grantee: Cíntia Carol de Melo Costa
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 11/17388-6 - Effects of solar radiation and air temperature on methane emission as associated with metabolic heat production and latent heat loss in ruminants
• Grantee: Alex Sandro Campos Maia
• Support Opportunities: Regular Research Grants